URINALYSIS

OUTLINE
• Introduction
• Indication
• Methods of urine collection
• Preservation of urine
• Examination of urine
• Conclusion

INTRODUCTION
• A urine analysis/ urinalysis (UA) is one of the
most common methods of medical diagnosis .
• Urinalysis is a convenient, cost effective and
non-invasive means of assessing kidney
function and providing an overall assessment
of our body’s health.
• Is readily available for screening many
diseases before symptoms occur.

INTRODUCTION
• Routine urinalysis includes assessment of the
physical characteristics of urine, chemical
analyses and a microscopic examination of
urine sediment.

INDICATIONS OF URINALYSIS
1. Information about function of the kidney e.g
in suspected renal disease like renal failure,
acute glomerulonephritis etc
2. Diagnosis of the urinary tract infection
3. Diagnosis of certain metabolic and systemic
disease eg. DM, nephrotic syndrome

INDICATIONS OF URINALYSIS
4. To monitor or assess progress of treatment in
conditions such as UTI, kidney stones, and
some kidney and liver diseases eg . Nephrotic
syndrome, glomerulonephritis, liver cirrhosis
5. As part of routine physical examination

METHODS OF URINE COLLECTION
• There are various methods of urine collection
depending on the test to be performed.
• Urine specimen must be properly collected in-
order to obtain reliable information from the
result of its analysis.
• Use a wide mouthed, clean and dry sterile
container.

METHODS OF URINE COLLECTION
• MIDSTREAM URINE: pass the first stream of
urine to clean the passage. Collect the next
stream in a clean and sterile container and
pass out the rest.
• CATHETER SPECIMEN: mostly used for
microbiological examination in critically ill
patient or in those with urinary tract
obstruction .
• SUPRAPUBIC TAP: mostly used in infants.

METHODS OF URINE COLLECTION
• FIRST MORNING URINE: Most concentrated
specimen, preferred for microscopic
examination and for the detection of
abnormal amounts of constituents such as
proteins or of unusual compounds such as
chorionic gonadotropin.

METHODS OF URINE COLLECTION
• 24 HOURS SPECIMEN:
• On day 1, the bladder must be emptied at the time
the collection is to begin and discarded. Thereafter
all the urine must be collected into the specimen
bottle.
• On day 2, the bladder is emptied at the end of the
scheduled time into the container. The urine sample
should be refrigerated during the collection period.

PRESERVATION OF URINE
• Urine sample should be processed within 1
hour of collection if held at room temperature
or else refrigerated at 2-8 degree C for not
more than 8 hours
• Methods of preservation:
1. Keep in refrigerator without any preservative
2. Urine preservatives

URINE PRESERVATIVES
• HCL
• Acetic acid
• Sodium bicarbonate
• Boric acid
• Toluene
• Thymol acid
• Formaldehyde

EXAMINATION OF URINE
• Physical examination(macroscopic)
• Chemical examination(dipstix analysis)
• Microscopic examination

PHYSICAL EXAMINATION
• Visual appearance
• Odour
• Turbidity
• Volume
• Specific gravity
• pH

PHYSICAL EXAMINATION
• VISUAL APPEARANCE;
Colour
Normal colour→ pale light yellow to a dark amber colour
Orange → Rifampicin, carrot, Vit C
Green- UTI, Asparagus
Red → haematuria, haemoglobinuria, myoglobinuria,
porphyria,nephrolithiasis UTI, rifampicin, Chlopromazine,
beets
Blue →blue diaper syndrome
Purple → Bacteriuria in patient with urinary catheter

• Brown-Gilbert syndrome,tyrosinemia,
hepatobiliary disease, fava beans,
• Black-Alkaptonuria, malignant melanoma
• White-pyuria, chyluria, lipiduria,
phosphaturia, hyperoxaluria,

PHYSICAL EXAMINATION
• Green or blue → biliverdin, pseudomonal UTI,
amitriptyline, methylene blue, iv
promethazine
• Yellow → concentrated urine, carrots
• Brownish-black → bilirubin, melanin,
methemoglobin, levodopa, methyldopa

PHYSICAL EXAMINATION
• ODOUR
1. Fresh normal urine has an aromatic smell.
2. Fruity or sweet odour: DKA
3. Ammoniacal odour: urea splitting bacterial infection,
prolonged bladder retention,
4. Pungent odour: UTI
5. Feacal odour: gastrointestinal-bladder fistulas
6. Sulphuric odour: medication and diet(asparagus)
7. Musty or mousy odour: phenylketonuria
8. Rancid odour: tyrosinaemia

PHYSICAL EXAMINATION
• TURBIDITY
Normal urine – clear
Cloudiness depends on PH and dissolves solids
composition.
May become turbid when left to stand
Generally due to gross bacteriuria.
In alkaline urine-amorphous phosphate and
carbonate, in acidic urine- amorphous urate

PHYSICAL EXAMINATION
• VOLUME
•Urine volume ranges btw 400-2000mls/24hrs
or 30-50mls / hr or 0.5-1.0 ml/min.
>3000ml/24hrs or 50ml/kg is referred to as Polyuria.
<400ml/24hrs is Oliguria
<100ml/24hrs is Anuria.
• Polyuria found in diabetes mellitus , diabetes insipidus
,chronic renal disease, acromegaly and myxedemarenal
tubular acidosis , hypercalceamia.
• Oliguria or Anuria suggests nephritis, urinary tract
obstruction, ARF,ESRD

PHYSICAL EXAMINATION
• It is used to assess the state of
hydration/dehydration of an individual or as an
indicator of the concentrating ability of the
kidneys.
• SG varies with the solute load to be excreted
(consisting primarily of NaCl and urea), as well as
with the urine volume
• Commonly used device is refractometer and
more recently a colorimetric reagent strip
method has been added to dipstick.

PHYSICAL EXAMINATION
• Normal range for urinary SG is 1.005 to 1.030;
dilute specimen1.000- 1.010, concentrated
sample 1.025- 1.030.
• Decreased USG-diabetes insipidus,
pyelonephritis, glomerulonephritis
• Increased USG is associated with glycosuria,
CHF, dehydration, adrenal insufficiency, liver
disease nephrosis,

PHYSICAL EXAMINATION
• URINARY pH
• It measures the acidity or alkalinity of the
urine. Range is 4.5 to 8.0.
• Acidic urine is < 4.5 e.g metabolic acidosis,
starvation, severe dehydration, chronic
diarrhoea
• Alkaline urine is > 8.0 e.g bacterial
contamination, urinary tract infection,
Fanconi’s syndrome

PHYSICAL EXAMINATION
• Patients with alkaline urine and UTI is suggestive
of a urease splitting organisms with production of
ammonia and phosphate crystals, predisposing to
calculi formation.
• Urinary pH can be measured with dipstick strip,
litmus paper and nitrazine paper.
• Dipstick strip test contains methyl red and
bromthymol blue
• Colour range : orange – yellow – green - blue
which covers the entire urinary pH range

CHEMICAL EXAMINATION
• Protein
• Glucose
• Ketones
• Blood
• Bilirubin
• Urobilinogen
• Nitrite
• Leucocytes esterase

CHEMICAL EXAMINATION
• PROTEINURIA
• Normally, small amount of filtered plasma
protein and protein secreted by nephrons
(Tamm-horsfall protein) can be found in
normal urine.
• Proteinuria is defined as urinary protein
excretion of > 150mg/day (10 to 20mg/dL).

CHEMICAL EXAMINATION
• Causes of proteinuria are as follows;
• Functional e.g severe muscular exertion,
pregnancy, orthostatic proteinuria
• Pre-renal e.g fever, CHF,
• Renal e.g acute glomerulonephritis, nephrotic
syndrome, renal tumor
• Post-renal e.g cystitis, urethritis, prostatitis,
bacterial or viral infection.

CHEMICAL EXAMINATION
• Dipstick test for proteinuria yields;
• Trace = 5 – 20mg/dL
• 1+ = 30mg/dL (< 0.5g/day)
• 2+ = 100mg/dL (0.5 – 1g/day)
• 3+ = 300mg/dL (1 – 2g/day)
• 4+ = > 1000mg/dL (> 2g/day)
• The reagent on the the dipstick test is
tetrabromophenol blue and a citrate pH 3 buffer.
• Colour range is from green to blue

CHEMICAL EXAMINATION
• Further evaluation of proteinuria usually
includes determination of 24-hour urinary
protein excretion, microscopic examination of
the urinary sediment, urinary protein
electrophoresis and assessment of renal
function.

CHEMICAL EXAMINATION
• GLUCOSE
• Ordinarily, urine contains no glucose, but less
than 0.1% of normally filtered glucose may
appear in the urine (i.e <130mg/24hrs).
• Glycosuria can be due to Diabetes Mellitus,
Endocrine diseases (eg. Pheachromocytoma,
Cushing's syndrome, thyrotoxicosis,
hyperpituitarism ) and pancreatic disease .

CHEMICAL EXAMINATION
• Glycosuria can also be found in physiological
states like pregnancy and lactation.
• A +ve test always requires exclusion of
diabetes mellitus.
• The dipstick reagent strips are specific for
glucose. The rely on glucose oxidase to
catalyse the formation of hydrogen peroxide,
and peroxidase to form chromogen which
produce a colour change.

CHEMICAL EXAMINATION
• Glucose +02 + H₂O→ glucoronic acid + H202
• H202 + potassium iodide chromogen → oxidised
chromogen + H₂O
• KETONES
• Normal urine contains no ketones
• Ketones are produced as a result of incomplete
metabolism of fats.
• Ketones include 2% acetone, 20% acetoacetic
acid and 78% beta-hydroxybutyric acid.

CHEMICAL EXAMINATION
• They are usually seen as a result of diabetic
ketoacidosis or some form of calorie
deprivation (starvation, anorexia, GI
disturbances), and vomiting.
• The dipstick strip test is based on the reaction
of sodium nitroprusside with acetoacetic acid
to produce a purple colour.

CHEMICAL EXAMINATION
• BLOOD
• Hematuria is the presence of an abnormal
number of RBC in urine.
• Seen in the following conditions:
damage/infection/tumors of urinary tract,
kidney trauma, renal infarcts, ATN,
nephrotoxins, physical stress, and
contaminants e.g menstruating women and
traumatic bladder catheterization

CHEMICAL EXAMINATION
• HEAMOGLOBINURIA is the presence of blood
pigments in the urine without the presence of
RBCs
• Associated with conditions that precipitate
hemolytic aneamias e.g. Paroxysmal nocturnal
hemoglobinuria, sickle cell disease, malaria,
transfusion reaction.
• The dipstick strip test is impregnated with
buffered tetramethylbenzidine (TMB) and an
organic peroxide.

CHEMICAL EXAMINATION
• The method depends on detection of the
peroxidase activity of hemoglobin, which
catalyses the reaction of hydroperoxide and
TMB.
• The color change ranges from orange through
pale to dark green and red cells,free hb and
myoglobin are all detected
• Microscopic examination of urine can also be
used for detection of blood.

CHEMICAL EXAMINATION
• BILIRUBIN
• It is a highly pigmented compound that is a
by-product of hemoglobin degradation.
• The detection of urinary bilirubin is an early
indication of liver disease (such as hepatitis,
hepatic cirrhosis and hepatocellular disease)
and its presence or absence can be used to
determine the causes of clinical jaundice.

CHEMICAL EXAMINATION
• Samples for bilirubin should be protected from
light as direct light will cause decomposition.
• The dipstick test strip is impregnated with a
diazonium salt which react with bilirubin to
produce colouration that varies from pink to
violet
• Results are interpreted as negative, small(+) ,
moderate(++), and large(+++) amounts of
bilirubin.

CHEMICAL EXAMINATION
• UROBILINOGEN
• A degradation product of bilirubin formed by
intestinal bacteria, usually found in urine in small
amounts(< 1mg/dL of urine).
• Elevated levels may indicate hemolytic anaemia,
large hematoma, liver cirrhosis
• The dipstick test strip is impregnated with an
Ehrlich’s reagent ( p-
dimethylaminobenzaldehyde) which react with
urobilinogen to produce colours that vary from
light to dark pink

CHEMICAL EXAMINATION
• NITRITE
• This test detect nitrite-reducing bacteria such
as the gram negative species that most
commonly cause UTI (E.coli, Enterobacter,
Klebsiella, Citrobacter and Proteus).
• They have enzyme that reduces nitrate
present in urine to nitrite.
• The dipstick strip test is impregnated with p-
arsanilic acid and tetrahydrobenzoquinoline.

CHEMICAL EXAMINATION
• The reaction is based on arsanilic acid in the
presence of nitrite converting to a diazonium
salt, which couples with the N-1-
naphthylethylenediamine to produce a pink
colour.
• It detect populations of bacteria at a value of
10⁵/ml or more, hence spot urine sample may
give a false negative result

CHEMICAL EXAMINATION
• LEUCOCYTE ESTERASE
• The presence of leucocyte esterase is indicative
of pyuria (presence of WBCs in the urine).
• The dipstick strip test is based on the action of
leucocyte esterase in catalysing the hydrolysis of
the derivatized pyrrole amino acid ester to
liberate 3-hydroxyl-5-phenylpyrrole which reacts
with a diazoniumsalt to produce a purple colour

MICROSCOPIC EXAMINATION
• Centrifuged, decanted urine aliquot leaves
behind a sediment of formed elements that is
used for microscopic examination

MICROSCOPIC EXAMINATION
• WHITE BLOOD CELLS: 2 – 5 WBCs/hpf is
considered normal. A high number of WBCs
indicates infection, inflammation or
contamination
• RED BLOOD CELLS: Erythrocytes greater in
number than 0–2/high-power field (HPF) are
considered abnormal. Is indicative of trauma,
particularly vascular injury, renal/urinary
calculi obstruction, pyelonephritis, or cystitis.
Hematuria in conjunction with leukocytes is
diagnostic of infection

MICROSCOPIC EXAMINATION
• EPITHELIAL CELLS:
Large, flat, squamous vaginal epithelia are often
seen in urine specimens from female patients, and
samples heavily contaminated with vaginal
discharge may show clumps or sheets of these cells
Renal epithelial cells are round, uninucleate cells,
and, if present in numbers greater than 2/HPF,
indicate clinically significant active tubular injury or
degeneration.

• Transitional bladder epithelial cells (urothelial
cells) may be flat, cuboidal, or columnar and
also can be observed in urine on occasion.
Large numbers will be seen only in cases of
urinary catheterization, bladder inflammation,
or neoplasm

• Miscellaneous Elements
Spermatozoa-In males, their presence may
indicate prostate abnormalities
Yeast cells
Parasites-Ova of the trematode Schistosoma
hematobium,Enteribius vermicularis,
Tricomonas vaginalis

• Bacteria-Normal urine is sterile and contains no
bacteria
• In fresh specimens, however, large numbers of
organisms, or small numbers accompanied by
WBCs and the symptoms of urinary tract
infection, are highly diagnostic for true infection
• Most pathogens seen in urine are gram-negative
coliforms (microscopic “rods”) such as Escherichia
coli and Proteus sp

• . Asymptomatic bacteriuria common in young
girls, pregnant women, and patients with
diabetes.
• This condition must be taken seriously
because, if left untreated, it may result in
pyelonephritis and, subsequently, permanent
renal damage.

MICROSCOPIC EXAMINATION
• CASTS
• Casts are precipitated, cylindrical impressions
of the nephrons. They comprise Tamm-
Horsfall mucoprotein (uromucoid) from the
tubular epithelia in the ascending limb of the
loop of Henle
• Casts in the urinary sediment may be used to
localize disease to a specific location in the
genitourinary tract.

MICROSCOPIC EXAMINATION
• CRYSTALS
Acid environment-calcium oxalate, which are
normal colorless octahedrons or “envelopes”; they
may have an almost starlike appearance.
amorphous urates, normal yellowred masses with a
grain of sand appearance.
Uric acid crystals found in this environment are
normal yellow to redbrown crystals that appear in
extremely irregular shapes, such as rosettes,
prisms, or rhomboids.

• Cholesterol crystals in acid urine are clear, flat,
rectangular plates with notched corners. They
may be seen in nephrotic syndrome and in
conditions producing chyluria and are always
considered abnormal
• . Cystine crystals are highly pathologic and
appear as colorless, refractile, nearly flat
hexagons, somewhat similar to uric acid.
These are observed in homocystinuria and
cystinuria

• Alkaline Environment-
• amorphous phosphates, which are normal crystals that
appear as fine, colorless masses, resembling sand.
• calcium carbonate crystals, which are normal forms
that appear as small, colorless dumbbells or spheres.
Triple phosphate crystals are colorless prisms of 3–6
sides, resembling “coffin lids.”
• Ammonium biurate crystals are normal forms
occasionally found in this environment, appearing as
spiny, yellow-brown spheres, or “thorn apples.”

Calcium oxalate
monohydrate crystals
Calcium oxalate
di hydrate crystals
Cystine crystals

A. Calcuim oxalate crystals.
B. Uric acid/urate crystals
C. Triphosphate crystals
D. Cystine crystals

CONCLUSION
• Urinalysis is a very useful screening and
diagnostic tool.
• If properly done, can yield a great deal of
information.
• It is important to store strips properly and
read at specific time.

THANK YOU FOR LISTENING

REFERENCES
• Edmund J. Lamb, Christopher P. Price, kidney
function test. In: Tietz textbook of clinical
chemistry and molecular diagnostics by Carl A.
Burtis, Edward R. Ashwood, David E. Burns. Fifth
edition © 2012. Pages 669 – 673.
• Jeff A. Simerville, William C. Maxted, John J.
Pahira, Urinalysis: A Comprehensive Review. In:
Am Fam Physician 2005;71:1153-62. copyright©
2005 American Academy of Family Physicians.